diff options
| author | Giles Cope <gilescope@gmail.com> | 2019-10-28 19:04:15 +0000 |
|---|---|---|
| committer | Giles Cope <gilescope@gmail.com> | 2019-10-30 06:12:49 +0000 |
| commit | d7869ec02281be58ed3857b545f258b81a6adb09 (patch) | |
| tree | b6a5197feb9f41a311bb1e3935d49d4417811899 /src/libcore/ops | |
| parent | 3fa9554d77960627cb2c983470bceacfeeb486b0 (diff) | |
Make ItemContext available for better diagnositcs.
Diffstat (limited to 'src/libcore/ops')
| -rw-r--r-- | src/libcore/ops/try.rs | 17 |
1 files changed, 15 insertions, 2 deletions
diff --git a/src/libcore/ops/try.rs b/src/libcore/ops/try.rs index 76fec1020f1..e8f35f8cf24 100644 --- a/src/libcore/ops/try.rs +++ b/src/libcore/ops/try.rs @@ -5,7 +5,7 @@ /// extracting those success or failure values from an existing instance and /// creating a new instance from a success or failure value. #[unstable(feature = "try_trait", issue = "42327")] -#[rustc_on_unimplemented( +#[cfg_attr(bootstrap, rustc_on_unimplemented( on(all( any(from_method="from_error", from_method="from_ok"), from_desugaring="QuestionMark"), @@ -17,7 +17,20 @@ message="the `?` operator can only be applied to values \ that implement `{Try}`", label="the `?` operator cannot be applied to type `{Self}`") -)] +))] +#[cfg_attr(not(bootstrap), rustc_on_unimplemented( +on(all( +any(from_method="from_error", from_method="from_ok"), +from_desugaring="QuestionMark"), +message="the `?` operator can only be used in {ItemContext} \ + that returns `Result` or `Option` \ + (or another type that implements `{Try}`)", +label="cannot use the `?` operator in {ItemContext} that returns `{Self}`"), +on(all(from_method="into_result", from_desugaring="QuestionMark"), +message="the `?` operator can only be applied to values \ + that implement `{Try}`", +label="the `?` operator cannot be applied to type `{Self}`") +))] #[doc(alias = "?")] pub trait Try { /// The type of this value when viewed as successful. |